"Yesterday my campaign posted a web video that made the claim that one of my primary opponents, Wil Cardon, failed to file income taxes for one of this companies, Eagle Gate," Flake wrote. "Because Eagle Gate operates out of the Cardon Group’s headquarters along with other British Virgin Island Insurance Companies the Cardons are involved in, we believed Wil was responsible for that company as well.

"When it was brought to my attention that he was not, I had the web video corrected immediately," he added. "My apologies, Wil. The error was unintentional, and I want to make sure my campaign is accurate in every detail."

The Flake campaign created a new Web video without the error in question.

http://youtu.be/-h8ATp7Eyl0

The campaign also emailed an additional statement.

"I want to be sure that each communication from my campaign is accurate. When it was brought to my attention that Wil wasn’t responsible for filing the 990 for Eagle Gate Insurance, as my web video claimed, I had it corrected immediately," Flake said. "Because Eagle Gate operates out of the Cardon Group’s headquarters along with other British Virgin Island Insurance Companies the Cardons are involved in, we believed he was responsible for that company as well.”

"The bottom line is, when Jeff makes a mistake, he corrects it immediately," Flake spokesman Andrew Wilder wrote in an email. "When Wil Cardon is wrong, he doubles down on distortion."

Democrats are gleeful over the primary fight. Also this week, Flake is set to go up on the air in television advertising. Democrats have been quick to point it out as a sign of his campaign's weakness.

But one GOP source aligned with Flake notes that the timing is only six weeks out from the beginning of early voting in the Aug. 28 primary.

Roll Call rates this race as Leans Republican. Former Surgeon General Richard Carmona is the presumptive Democratic nominee in the race to replace retiring Sen. Jon Kyl (R).